1. Technical Field
The present invention relates to a liquid ejecting head which is provided with a piezoelectric element having a piezoelectric layer made of a piezoelectric material and an electrode and discharges liquid droplets from nozzle openings, a liquid ejecting apparatus, and a piezoelectric element.
2. Related Art
Some piezoelectric elements which are used in liquid ejecting heads have a configuration in which a piezoelectric layer made of a piezoelectric material having an electromechanical transduction function, such as a crystallized dielectric material, is sandwiched between two electrodes. Such a piezoelectric element is mounted on a liquid ejecting head as, for example, a flexural oscillation-mode actuator device. Here, representative examples of the liquid ejecting head include an ink jet recording head in which a part of a pressure generating chamber communicating with nozzle openings which discharge ink droplets is formed by an oscillation plate and the oscillation plate is deformed by a piezoelectric element to pressurize the ink in the pressure generating chamber, thereby discharging ink droplets from the nozzle openings.
A piezoelectric material which is used as a piezoelectric layer of the piezoelectric element is required to have high piezoelectric characteristics, and representative examples of the piezoelectric material include lead zirconate titanate (PZT) (see JP-A-2001-223404). However, a piezoelectric material which is lead-free or in which the content of lead is suppressed is demanded from the viewpoint of environmental problems. Examples of the piezoelectric material containing no lead include BiFeO3-based piezoelectric materials containing Bi and Fe (for example, see JP-A-2007-287745).
However, when a bismuth ferrate-based piezoelectric layer having a perovskite structure is manufactured, there is a problem in that cracks are easily caused. This problem occurs not only in ink jet recording heads, but also in other liquid ejecting heads which discharge liquid droplets other than ink, and piezoelectric elements being used in devices other than the liquid ejecting head also have this problem.